Used cars are always full of surprises. I decided to pull my seats and carpets for cleaning on the 2010 H3 I just purchased (yes, it was that dirty). Found some water under the carpet on passenger rear, and passenger front carpet pad was stuck down, indicating previous leak. With a bit of searching about sunroof drains, I started the process to open them up. To my surprise, when I pulled the passenger side front grommet, it was open. If there was even an X pattern in it, it was gone and so cleanly that I'm starting to think Hummer decided by 2010 that the X was a bad idea. Anyone with a 2010 that can verify or disprove this?

So, I decided front drains weren't an issue and opened up the back to get to the rears. Unfortunately, that's when I discovered the underside of the rear cargo area cover was soaked through. Ended up pulling it all out and this is the result:



The rear drains appeared to be intact and correctly seated, although the tiny openings were likely clogged. Still didn't seem to explain all the water in the cargo area. Headliner was dry and doesn't appear to have any stains. A bit more investigation online pointed me to the clips holding on the fender flares. And here is what I noticed:



Notice the drip line down the side under the clip and then along the horizontal surface leading into the cargo area. Very faint indication of this on another clip. This mat goes all the way up to cover this horizontal surface, then I suppose it becomes a sponge and transfers the water throughout. The other side (under the amp and sub) wasn't wet on the upper surface, but I haven't pulled the sub/amp to see if there are any drip lines.

So the question I haven't been able to find an answer to with searches of every combination of wet, cargo, area, and others: Has anyone else seen this amount of water coming through the clips? It is hard to imagine that much coming through (as wet as the cargo area covering is), but I don't see any other likely place for a leak. I hope to silicone up the clips as I've seen on other threads and be done with it, but if there are other places I should be looking, please let me know.

 

Usually clips used in an application like that will have a type of foam gasket on them. I wonder if yours were removed and replaced without the gaskets? (This isn't the correct clip, just something with a gasket)

 

You can always hit them with a bit of silicon caulk and they'll seal right up.